window.onload = function () {
    menuWidth();
}
window.onresize = function () {
    menuWidth();
}

function menuWidth() {
    var windoWidth = document.documentElement.clientWidth;
    var headerTop = document.getElementsByTagName('header')[0];
    var logoW = headerTop.getElementsByClassName('logo')[0];
    var telW = headerTop.getElementsByClassName('tel')[0];
    var oli = headerTop.getElementsByTagName('li');
    for (var i = 0; i < oli.length; i++) {
        oli[i].style.width = (windoWidth - (logoW.offsetWidth + telW.offsetWidth)) / oli.length + 'px';
    };
};